Uniformly-tensioned loom let-off



Dec. 13, v1927.

R. G. TURNER UNIFORILY TENSIONED LOOM LET- OFF Filed vec. 50. 192s [iff/zalm whether the warp .t0 the drum without Patented Dec. 13, 1927.

PATE

NT OFFICE.

UNmonMLY-TENSIONED Loom LET-oFF.

Application led December 30, 1926.v Serial No. 158,092.

This invention relates to tension devices for loom let-offs and it is the general ob- `ect of the invention to provide means wherey the original tension of the warp may be established after a pick-out. the weaving of certain fabricsy it is highly desirable to preserve the same warp tension throughout the weaving operation and it is also necessary to be able to slacken l the warp to permit a pick-out and then to restore the original tension so that the first pick after the pick-out will be layed under the same tension as those picks layed prior tothe pick-out. 'It is an important object of my present invention to accomplish the aforesaid desired result' by means of a dif ferential gearing interposed between a friction device and the warp supply coupled with means for moving the system of gearing manually.

It isa further object of my invention to provide a friction head and a warp supply connected together by differential planetary gearing so `arranged that when the warp is loose at the time of pick-out the planet gears may `be moved manually to move the warp supply while the friction device remains at rest, theV increasing tension of the warp being ultimately equal to that-of the friction device so that said friction device may turn, thus restorin the warp to its normal tension. l

-`It is a more particular object Qf my invention to provide a warp deliver drum to be used in conjunction with a cree and having lrolls which may be pressed against the drum approximately at the points where the yarn is tangent thereto so as to cause all of the warp threads to lie in a plane to be fed cross-overs. A pair of such rolls may be used so as to be effective is being moved normally toward cloth forming position or reversely at the time of pick-out.

j With these and other objects which will appear as the description proceeds, my in- -Yvention relates to arrangements and combmations of parts hereinafterset forth, and

fmoreparticularly pointed out in the claims.

In the accompanying drawings, wherein a convenient embodiment of my invention 1s shown,

' e Fig. 1 is an end elevation of a loom having my invention applied thereto,

Fig. 2 is a top plan view of that end of the loom shown in Fi 1, V

Fig. 3 is an enlarged horizontal section on line 3 3 of Fig. 1,

Fig. 4 is a vertical section on line 4*'4 of Fig. 3 but showing the parts in substantially the same scale as in Figs. 1 and 2.

Referring'te the drawings a loom frame 0 supports warp mounted for on shaft 12 carried by loom bearings 13 one of which is shown in the drawings. The warp W may be drawn from a creel and may be led over free yrotation delivery drum 11 loosely' fixed guide bar 14 to movable rod 15, and

hand lever 18 pivoted to the loom frame at 19 and extend forwardl to rest on a block 20 through which extends a screw 21. Said screw is mounted in a fixed bracket 22 and the block is held against rotation by engagement with a portion of said bracket eX- tending parallel to the screw. By means 0f hand wheel 23 said screw may be turned to raise or lower the block and thus vary the vertical position of the hand lever 18. The latter may be flexed over the block to the position indicated in dotted lines in Fig. 2 when it is desired to disconnect said lever from the adjustable securing means. A depending arm 24 on the lever vis connected to a rearwardly extending rod 25 which in turn is connected to lever 26 and the other arm of which is connected to one end Vof a flexible friction band 27 as at 28. The other end of said band is fixed with respect to the loom frame as atV around and in frictional con? one arm ofrbell crank to the shaft 12 by -means of a hey el and secured to the Web provide said arm .with a stud 4:2A loosely mountedtherein and having on the left- V end a pinion i3 of relatively small'diameter to mesh with the gear le bolted or otherwise 45 of the friction head 80. A` second 'pinion (i6 somewhatlarger than the pinion e?) and having more'teeth 1` .thereoiiis secured tothe other end of the have provided y .restoration of normal n pick-out, the device including a system of i 55 Y andv their gears.

,the friction bandv 27 and as 'gear 47 is secured `moved While the yoriginal tension prior stud 42, said larger pinion meshing with a gear 47 of somewhat smaller pitch diameter than the gear 44 and secured to spider i8 in any approved manner. a

Under normal conditions the feeding of the Warp W through the loom and around the `drum 11 causes the latter to overcome the friction between band 27 and friction head .30.` Under these conditionsthe gearing is moved as a unit. about shaft 12, there being no relative movement bet-Ween the pinions i At the time ofpiclrout the hand `Wheel 32 will be turned to give shaft 12 a'rever'se movement; At this time friction head 30 will be held against movement by the drum 'is turning in a reverse direction there is comparatively little strain on the yarn and gear 44C' Will be at rest with pinion 43 `moving around the same. As pinion 48 rotates the larger pinion lGwill also rotate to v'cause a movement on the part of gear 47. n Since the to the'drum thelatter is friction head is at rest. After the pick-out it isdesired to restore the originalftension,

lhand Wheel 32 Will be turned in the reverse direction, the friction head 30 still being Vheld against movement by the band 27. The

' parts will move in a direction the reverse of that already described so as to take up the slack of the Warp lN. During'this reverse movementv the drum vWill rotate until the Yfell of the cloth lis against the loom reed. This will arrest the reverse movement of the yarn andthe friction head will begin to turn, thus putting the Warp under the loom. the Warp permitted by the friction elements. From the foregoing it will be seen that I Warp tension after a differential gearing'between the friction ele- Will lie to one side of the 'extension 52 engages stop 55, the

has been completed and tostarting up the It is therefore impossible to subject' 'll'CtOli mea-HS, and

with a pressure greater than thatl relative movement between ery a let-off Which permits y aA ing. can be controlled from the front of theV loom so as to vary thewarpifpressure at. will. Furthermore, it .will be seen thatthe 'fric- .tion head and the Warp" delivery; drum are so related that one will usually remain stationary VWhile vthe other turns during the restoration of the normal tension, i. e., when slack is being talen'up the friction head will remain at rest and When the Warp `drum is tightened to the proper tension the friction band will then move to prevent an iiicrease oi'pressure. Y

Referring to l have provided a pair ofrolls held yieldingly against the friction drum substantially at the points Where the Warp :threads are tangent thereto. These devices are substantially similar and i will describe but oiieof them. A. shaft 50 hassecured at each end tened tothe loomfranie '54, A vfixed stop 55 l i it Wiii be seen 'uwerV is positioned for engagement'with*extension 52 when the levers are thrown iniinop'erati've posit-ion. is to be understood-"that there vare tivo levers for each shaft 50, one on each sideoftheloom, and said leversafrord suprell 'preferporting means for a pressure ably, though not I necessarily, mounted-on the lever v51.I 7 Y Under normal conditions 'the spring 53 rotatably the roll against the War-p;

from the drumnntil spring' '53 to holdthe roll eleroll may beraisedaivay being sufficiently 'strong shaft l50 to hold i y When it is' desired to alter any of the Warpthreads the vatedpvith the axis thereof below shaft 50.

In this Way l prevent thel ythreads from crossing each other as they are led tothe drum, Whether the latter be' advancingnormally or are being reversed. i Y Having thus described;v my Will be apparent that cli-anges and modiea tions maybe made therein b those skilled in the art Without departing om Vthe spirit 'and scope V of the invention, and Fdo not l Wish Vto be limited to the details herein disclosed, but what I claim'is: Y, v

'1. ln let-off mechanisms for loomsfga` warp delivery means,v friction meansnormally effective Vto resist movemei-itlof' the Warp delivery means,'differentialgearing inte osed between the Warp delivery means an the meansV for manually moving'A the `differential gearing' to cause a means and the friction means.r

2. lln i let-off mechanismsY for looms` a Warp delivery means, .friction meansincluding a movableY member, a gearfor 'each of said means, vand `manually operablefplanet- 'invention4 it the Warp' deliv-V ary gears meshing with the gears for said means, said planetary gears havin the same angular movement when moved a out either gear.

3. In let-off mechanisms for looms, a warp delivery means, a friction means normally resisting movement of the Warp de` livery means, a gear moving with the Warp delivery means, another gear of different size from the first named gear movin with the friction means, a pair of connecter? planetary pinions of different sizes, the smaller pinion meshing with the larger gear and the larger pinion meshing with the smaller gear, and a device to cause said pinions to move in unison about the gears.

4. In let-off mechanisms for looms, a- Warp delivery means, a friction means normally resisting movement of the delivery means, and having a rotating member, a gearing unit for the member including a gear secured thereto and a pinion meshing with the gear, a second gearing unit for the Warp delivery means having a gear moving with said dellvery means and a pinion meshing with the gear therefor, the ratio between the gear and pinion being different for the two units, and means to move the pinions in unison.

5. In let-off mechanisms for looms, a Warp delivery means, a friction means normally resisting movement of the delivery means, and having a rotatable member rotatable about the axis of the Warp delivery means, gears of different sizes secured one to each of said means, a pair of pinions of different sizes meshing with the gears and movable as a unit about the axis of the delivery means and member, and means for manually moving said pinions as a unit about said gears.

6. In let-off mechanisms for looms, a

war delivery means, a rotatable friction hea means to resist movement of the friction head under normal conditions, two pair of gears, the members of one air being of different sizes and being one fixed to the delivery means and the other fixed to the friction head, the other pair of gears being of different sizes, the gears of one pair meshing with the gears of the other pair, and manual means for moving one of said pairs around the other While the friction head is held stationary to cause a relative movement of the delivery means.

7. In let-off mechanisms for looms, a warp delivery means, a friction head, a relatively fixed member to resist movement of the head, a gear fixed to the delivery means, another ear of different size fixed to the friction ead, a pair of planetary pinions meshing with the gears, and means to move said pinions about the gears to cause movement of the delivery meanswhen the relativelv fixed member resists movement of the friction head.

8. In let-off mechanisms for looms, a shaft, Warp delivery means loosely mounted on the shaft, a friction head loosely mounted on the shaft, means to resist movement of the friction head, a gear moving with the delivery means, another gear of different size moving with the friction head, planetary pinions of different sizes meshln with e gears and movable together a out a common axis, a support secured to said shaft on which the pinions are mounted, and manual means to rotate the shaft when the friction head is held against movement to cause angular movement of the warp delivery means.

In testimony whereof I have hereunto affixed my signature.

RICHARD GREENLEAF TURNER. 

